Recently, a demand for reducing power consumption of a semiconductor integrated circuit is increased, more specifically, in the following case.
For example, a plurality of chips is stacked in order to enlarge the semiconductor integrated circuit. In this case, heat between the chips is hardly dissipated. However, if a sufficient radiator such as a heat sink is attached in order to dissipate the heat between the chips, the semiconductor integrated circuit can be thin. Accordingly, reduction of the power consumption (particularly, peak power) of the semiconductor integrated circuit is required when the chips are stacked.
There is well known a technology called Dynamic Voltage and Frequency Scaling (hereinafter referred to as “DVFS”). In the DVFS, a power consumed in operating the semiconductor integrated circuit is reduced by operating the semiconductor integrated circuit at the minimum voltage and frequency.
However, the conventional control circuit (hereinafter referred to as “VFC (Voltage Frequency Controller)”) that realizes the DVFS is individually developed in each application. Therefore, the conventional VFCs does not have versatility and high reusability.